1. Field of the Invention
The present invention relates to color processing including processing for expanding a color gamut.
2. Description of the Related Art
In general, upon comparison of an sRGB color space popularly used as a standard color space of a color monitor with a color gamut that can be reproduced by an ink-jet printer, the color gamut of the ink-jet printer is much broader than the sRGB color space in a cyan color range, a red color range using spot color inks, and the like. Hence, in order to realize more favorable color reproduction, the ink-jet printer reproduces memory colors such as blue of a sea, orange of a setting sun, and the like using the broader color gamut upon outputting an image compliant to the sRGB color space.
As a technique for fully using the dominant color gamut by the printer, a technique described in U.S. Pat. No. 6,765,586 is known. This technique includes hue shift processing for converting the shape of an input gamut to approach that of an output gamut, and gamut expanding processing for explaining the input gamut.
However, when the color gamut of the color printer is further expanded, if the same gamut expanding processing as the conventional processing is applied, the chroma level becomes too high beyond necessity, resulting in extremely vivid colors. Hence, less than a favorable image is obtained.